C++ STL stable_sort用法

一：功能

      对区间内元素进行排序，保证相等元素的顺序（稳定排序）

二：用法

#include <iostream>

struct Record {
	std::string label;
	int rank;
};

int main() {
    std::vector<Record> data {{"q", 1}, {"f", 1}, {"c", 2}, {"a", 1}, {"d", 3}};

    std::ranges::stable_sort(data, {}, &Record::label);    
    std::ranges::stable_sort(data, {}, &Record::rank);
    for (auto &v : data) {
        std::cout << v.label << "-" << v.rank << " ";
    }
    std::cout << "\n";
}

#include <algorithm>
#include <array>
#include <iostream>
#include <string>
#include <vector>
 
struct Employee
{
    int age;
    std::string name; // Does not participate in comparisons
};
 
bool operator<(const Employee& lhs, const Employee& rhs)
{
    return lhs.age < rhs.age;
}
 
#if __cpp_lib_constexpr_algorithms >= 202306L
consteval auto get_sorted()
{
    auto v = std::array{3, 1, 4, 1, 5, 9};
    std::stable_sort(v.begin(), v.end());
    return v;
}
static_assert(std::ranges::is_sorted(get_sorted()));
#endif
 
int main()
{
    std::vector<Employee> v{{108, "Zaphod"}, {32, "Arthur"}, {108, "Ford"}};
 
    std::stable_sort(v.begin(), v.end());
 
    for (const Employee& e : v)
        std::cout << e.age << ", " << e.name << '\n';
}